Found this recipe at Heart 4 My Home and I just had to copy it over to here to try... sounds so yummy!

Grandma's Buttermilk Brownie Cake

by Connie Mrachek of Charles City, IA

Cake:
2 cups granulated sugar
2 cups all-purpose flour
¼ cup cocoa powder
½ cup vegetable oil
½ cup butter or margarine
½ cup reduced-fat buttermilk
1 teaspoon baking soda
2 eggs, lightly beaten
1 teaspoon vanilla extract

Frosting:
½ cup butter or margarine
¼ cup cocoa powder
1/3 cup reduced-fat buttermilk
1 (1-pound) box confectioners’ sugar
1 teaspoon vanilla extract

Preheat oven to 400F. Grease a 15 x 10-inch baking pans.

To prepare brownies, combine granulated sugar, flour and cocoa; mix well.
Combine 1 cup water with oil and butter in a medium saucepan. Bring to a boil; add to flour mixture and mix well. Add buttermilk, baking soda, eggs and vanilla. Beat well by hand and pour into pan. 20 to 22 minutes, until a wooden pick inserted in the center comes out almost clean. Cool completely on wire racks.

To prepare frosting, combine butter, cocoa and buttermilk in a saucepan; bring to a boil. Remove from heat. Gradually beat in confectioners’ sugar and vanilla with a mixer at low speed. Spread evenly over cooled brownies.

Makes about 3 dozen brownies.